Research On Spatial Positioning Method With Total Station Based On Opto-electrical Scanning Angle Measurement And Ultrasonic Ranging

Total station spatial positioning measurement technology is extensively appliedin large-scale measurement of industrial assembly and manufacturing with itsflexibility and adaptability. The existing total station technology has some principlelimits, for instance, the technology based on spherical coordinates can only be appliedin single task measurement inefficiently which is limited by its laser interferenceranging principle; and the technology based on spatial angle intersection has lowaccuracy due to the dependence on the structure constrains of measurement spacewhich lacks distance constrains. Therefore, in order to achieve total station spatialcoordinate measuring technology with the advantages of multi-task, real-timemeasurement and high accuracy, this thesis presents a novel total station measurementmethod by studying spatial angle measurement based on laser scanning and highlyaccurate ultrasonic ranging method. The main research work of this thesis is asfollow:1、 Based on spherical coordinate measurement principle, a novel total stationspatial positioning measurement method was presented. This method calculated thecoordinates by using the spatial angles through laser scanning and the distance fromthe circularly array ultrasonic ranging systems. With the spatial divergence angles ofthe laser scanning and ultrasonic arrays, this method could measure the spatialcoordinates in multi-task and real-time with a single station.2、 The spatial angle measurement principle based on laser scanning and thecalibration method for laser planar parameters were stated and studied. The method tofuse the angle and distance was presented, i.e., the coordinates of ultrasonic rangingsystem in laser scanning station could be calibrated through inter-scanning withmulti-stations. The spatial positioning principle based on multi-planar constrains andultrasonic ranging was proposed.3、 A highly accurate opposite-type ultrasonic ranging method combined roughand fine measurement for time-of-fight(ToF) was presented. The rough measurementextracted the integral multiple of ultrasonic cycles in ToF by using cross correlationwith feature point, and then the fine measurement accurately modified the decimalpart in ToF from the phase difference between the emitted and received signals. This method could achieve high accuracy due to the high SNR signal without thedistractions from reflectors.4、 Temperature is a mainly factor to interference the sound velocity, whichcritically influences the ranging accuracy. In order to solve the unsteady andheterogeneous temperature distribution in industrial measurement field, acompensation method based on3D temperature field construction by using finiteelement algorithm was proposed, which could fit the temperature distribution in themeasurement space through the boundary conditions. Therefore, the sound velocitycould be compensated accurately.5、 The uncertainty sources of this spatial positioning method were analyzed,including the uncertainty of angle measurement using laser scanning and ultrasonicranging. The propagation model of uncertainty and the optimum measurement methodof the measuring target were derived. The experiments were designed to verify thefeasibility and accuracy of this method.